Embodiments of the present invention provide a method and apparatus for updating device driver control data. More particularly, embodiments of the present invention provide a method and apparatus for modifying the control data that is used by a device driver in a computer system, or for providing new control data to the device driver.
A device driver is a program that controls a peripheral device in a computer system. An example of a device driver is a video driver, which controls a video device, such as a cathode ray tube (CRT) monitor. Other examples of device drivers are a keyboard driver, a mouse driver, or a modem driver. In a computer system, device drivers are typically stored on the disk drive. Device drivers contain control data that specify parameters which are used by the device driver to control the peripheral. For example, the control data for a video driver includes timing or mode data, such as dot clock, control register, and watermark data. Dot clock and control register data specify parameters for the timing of signals that are sent to the video display device, and watermark data specifies parameters for the input bandwidth to the video display device.
It is periodically necessary to modify the control data for a device driver. For example, the timing control data for a video device driver may have to be changed when the system configuration changes, such as when a new processor is installed in the system. In addition, it may be necessary to change the device driver control data to fix a flaw in the system. Another example of modifying device driver control data is adding new video driver control data to support a new video display mode that is being added to the system, such as the addition of 1024 bit xc3x97768 bit xc3x9716 bit resolution capability, or a new frequency or clocking scheme. Previously, device driver control data was stored on the same storage medium as the device driver (e.g., a disk memory). In some systems, the control data was hard-coded into the device driver. In other systems, the control data was stored separately on the storage medium. If. the device driver control data is stored on a disk memory, for example, then updating the control data requires that the data stored in the disk memory xe2x80x9cthe disk imagexe2x80x9d) be modified. If the driver control data is hard-coded into the driver, then the only practical way to modify the control data is to install a new driver. This can be expensive because drivers are typically as large as one-half a million lines of code, and because different drivers may be produced by different manufactures. Even if the driver control data is stored separately on the disk memory, it is necessary to perform the sometimes expensive and difficult task of modifying the disk memory. If an organization is operating a network that has hundreds of personal computers, for example, this may require the organization""s Information Technology (IT) department to back-up and restore the disk image for each of these computers because the disk memories may contain user data or other software.
Based on the foregoing, there is a need for a method and apparatus for updating device driver control data without modifying the contents of the storage medium that stores the device driver.